INFO: task hung in tty_ldisc_kill (2)

Status: auto-obsoleted due to no activity on 2025/10/22 01:21
Subsystems: serial
[Documentation on labels]
First crash: 378d, last: 378d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in tty_ldisc_kill serial 1 2 700d 702d 0/29 auto-obsoleted due to no activity on 2025/01/03 09:15

Sample crash report:
INFO: task syz.2.2086:14272 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2086      state:D stack:27048 pid:14272 tgid:14272 ppid:10065  task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142
 unregister_netdev+0x15/0x60 net/core/dev.c:12246
 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613
 tty_ldisc_release+0x1a4/0x200 drivers/tty/tty_ldisc.c:781
 tty_release_struct+0x2a/0xd0 drivers/tty/tty_io.c:1681
 tty_release+0xcb0/0x1640 drivers/tty/tty_io.c:1852
 __fput+0x449/0xa70 fs/file_table.c:468
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffb1db8ebe9
RSP: 002b:00007fffe74c0088 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000094150 RCX: 00007ffb1db8ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007ffb1ddb7da0 R08: 0000000000000001 R09: 0000000be74c037f
R10: 0000001b30a20000 R11: 0000000000000246 R12: 00007ffb1ddb5fac
R13: 00007ffb1ddb5fa0 R14: ffffffffffffffff R15: 00007fffe74c01a0
 </TASK>
INFO: task syz.6.2087:14287 blocked for more than 147 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.2087      state:D stack:26944 pid:14287 tgid:14274 ppid:12563  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:17363
 genl_family_rcv_msg_doit+0x1bb/0x300 net/netlink/genetlink.c:1110
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1a2b98ebe9
RSP: 002b:00007f1a2c76b038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1a2bbb6270 RCX: 00007f1a2b98ebe9
RDX: 0000000024040890 RSI: 00002000000006c0 RDI: 0000000000000004
RBP: 00007f1a2ba11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1a2bbb6308 R14: 00007f1a2bbb6270 R15: 00007fffaf86cb48
 </TASK>
INFO: task syz.9.2089:14289 blocked for more than 150 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.2089      state:D stack:26952 pid:14289 tgid:14288 ppid:8467   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:17363
 genl_family_rcv_msg_doit+0x1bb/0x300 net/netlink/genetlink.c:1110
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f17fbf8ebe9
RSP: 002b:00007f17fcd1e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f17fc1b5fa0 RCX: 00007f17fbf8ebe9
RDX: 0000000000000084 RSI: 0000200000000200 RDI: 0000000000000003
RBP: 00007f17fc011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f17fc1b6038 R14: 00007f17fc1b5fa0 R15: 00007fffe179d538
 </TASK>
INFO: task syz.4.2092:14314 blocked for more than 152 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2092      state:D stack:26504 pid:14314 tgid:14313 ppid:5863   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 rtnl_lock net/core/rtnetlink.c:80 [inline]
 rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 __sys_sendto+0x3bd/0x520 net/socket.c:2228
 __do_sys_sendto net/socket.c:2235 [inline]
 __se_sys_sendto net/socket.c:2231 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2231
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f952df90a7c
RSP: 002b:00007f952ed4eec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f952ed4efc0 RCX: 00007f952df90a7c
RDX: 0000000000000020 RSI: 00007f952ed4f010 RDI: 0000000000000006
RBP: 0000000000000000 R08: 00007f952ed4ef14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000006
R13: 00007f952ed4ef68 R14: 00007f952ed4f010 R15: 0000000000000000
 </TASK>
INFO: task syz.4.2092:14315 blocked for more than 154 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2092      state:D stack:27816 pid:14315 tgid:14313 ppid:5863   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
 rtnl_lock net/core/rtnetlink.c:80 [inline]
 rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6952
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f952df8ebe9
RSP: 002b:00007f952ed2f038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f952e1b6090 RCX: 00007f952df8ebe9
RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000006

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/23 01:17 linux-next 7fa4d8dc380f bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in tty_ldisc_kill
* Struck through repros no longer work on HEAD.